A very common issue folks with SQLite run into is that concurrent
read/writes can return `SQLITE_BUSY`s.

Via [0], [1] and best practices used across the industry, we can enable
the Write Ahead Log (WAL) which makes it possible to concurrently read
and write.

This requires we provide a way to manage the PRAGMAs that SQLite needs
to use to enable this functionality, as well as a few options via [0]
I've not tested too much without, but with them seems like it's probably
OK.

This also resolves future issues we'll see when trying to write a large
amount of data to the database while reading+writing Policy Violations.

Closes #404.

[0]: https://blog.pecar.me/sqlite-prod
[1]: https://www.jvt.me/posts/2022/01/20/go-append-querystring/